Oil found within a subterranean formation is recovered or produced through wells called production wells which are drilled into the subterranean formation. Generally, a large amount of the oil is left in the formation if it is produced only by primary depletion, i.e., where only formation energy is employed in recovering the oil. Only a small fraction of the original oil-in-place in a hydrocarbon-bearing reservoir is expelled by primary production or natural mechanisms. Where the initial formation energy is inadequate or has become depleted through production from the well, supplemental processes referred to as secondary, and tertiary, and quaternary recovery operations are utilized in order to recover a larger percentage of the in-place oil. Waterflooding and surfactantflooding are processes well known in the art to recover the vast quantities of oil which remain in the formation after primary oil recovery operations. Designing new surfactant systems of high oil recovery efficiency and good phase stability remains a goal in this technology. This invention relates to chemicals suitable for use in enhanced recovery of crude oils from subterranean formations.
It is an object of this invention to provide new chemical compositions useful in oil recovery.
A further object of this invention is to produce surfactant system useful in surfactantflooding. Particularly, the surfactant systems should be useful in environments comprising hard brines as well as fresh or fresher water.
Yet another object of this invention is to provide an oil recovery process using the surfactant systems of this invention.
These and other objects, advantages, details, features and embodiments of this invention will become apparent to those skilled in the art from the following detailed description of the invention and the appended claims.